Schrack Technik PQC User manual

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USER MANUAL
POWER FACTOR CORRECTION
Power Quality Controller PQC

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Contents
1 SAFETY 7
1.1 OBJECTIVE 7
1.2 SAFETY INSTRUCTIONS 7
1.3 INTENDED USE 8
1.4 IMPROPER USE 8
1.5 REPAIR 9
1.6 SYMBOLS USED 9
2 TECHNICAL DATA 10
3 INSTRUMENT DESCRIPTION 14
3.1 FUNCTION 14
3.2 REGENERATION 14
4 MOUNTING THE INSTRUMENT 15
4.1 SUITABLE LOCATION 15
4.2 INSTALLING THE INSTRUMENT 15
5 INSTALLATION 17
5.1 ELECTRICAL CONNECTIONS 17
5.2 EARTH CONNECTION 18
5.3 SUPPLY VOLTAGE 19
5.4 VOLTAGE MEASUREMENT 20
5.5 CURRENT MEASUREMENT 21
5.6 OUTPUT RELAYS (CONTROL OUTPUTS) 23
5.7 CONNECTION DIAGRAMS OF ALL PQC INSTRUMENT TYPES 24
5.7.1 CONNECTION DIAGRAM:VERSION PQC 1202401-XX 24
5.7.2 CONNECTION DIAGRAM:VERSION PQC 1202403-XX 25
5.7.3 CONNECTION DIAGRAM:VERSION PQC 0602401-XX 26
5.7.4 CONNECTION DIAGRAM:VERSION PQC 1204801-XX 27
5.7.5 CONNECTION DIAGRAM:VERSION PQC 1204803-XX 28
5.7.6 CONNECTION DIAGRAM:VERSION PQC 0614801-XX 29

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5.7.7 O PTIONS FOR CONNECTING THE AUX POWER SUPPLY FOR PQC XXX480X-XX VERSIONS 30
6 COMMISSIONING (INITIAL START-UP) 31
6.1 A LARM FUNCTION 31
6.1.1 L IST OF ALARMS AND MESSAGES 31
6.2 S AFETY PRECAUTIONS BEFORE START - UP 32
6.3 F UNCTIONAL CHECKOUT 32
6.4 C ONFIGURATION 32
6.5 A UTOMATIC COMMISSIONING 32
6.5.1 A UTOMATIC CONNECTION IDENTIFICATION 33
6.5.2 A UTOMATIC IDENTIFICATION OF THE CONNECTED CAPACITOR STAGES 33
6.5.3 C ALCULATION OF C / K 34
7 DESCRIPTION OF THE MENU 35
7.1 M ENU OVERVIEW 36
8 MAIN MENU 38
8.1 PQC INITIAL START - UP 39
8.1.1 L ANGUAGE SELECTION ON START - UP 39
8.1.2 S TART - UP 41
8.2 PQC OVERVIEW 41
8.2.1 D ISPLAYED PARAMETERS 42
8.3 C ONTROL DIAGRAM 44
8.3.1 S CALE 44
8.4 M ANUAL CONTROL 45
8.4.1 S TAGES MENU 46
8.5 S ETTINGS 47
8.5.1 S ETTABLE CONTROL PROFILES 47
8.5.2 T YPICAL CONTROL PROFILE APPLICATIONS 47
8.5.3 G ENERAL SETTINGS 54
8.6 I NFO / STATUS 60
8.6.1 PQC STATUS 61
8.6.2 C ORRECTIVE POWER 61
8.6.3 C APACITOR STAGES TABLE 62
8.6.4 C APACITOR STAGES RATING DIAGRAM 62
8.6.5 S WITCH CYCLE DIAGRAM 62
8.6.6 V OLTAGE AND CURRENT HARMONICS DIAGRAM 63

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8.6.7 VOLTAGE AND CURRENT HARMONICS TABLE 63
8.6.8 MANUAL FREQUENCY ANALYSIS 64
8.7 ABOUT PQC SUBMENU 65
8.8 FACTORY DEFAULT SETTINGS 65
8.9 UPDATE 69
9 INSTRUMENT VERSIONS 70
10 MAINTENANCE 72
10.1 CLEANING 72
11 DECOMMISSIONING AND REMOVAL, STORAGE AND
DISPOSAL 73
11.1 DECOMMISSIONING AND REMOVAL 73
11.2 STORAGE 74
11.3 DISPOSAL 75
12 GENERAL OPERATION 76
12.1 TROUBLESHOOTING 76
13 SCOPE OF SUPPLY 78
Figures
Figure 1 PQC dimensions in mm ............................................................................................ 15
Figure 2 Connection diagram for PQC 1202401-XX ............................................................. 24
Figure 3 Connection diagram for PQC 1202403-XX ............................................................. 25
Figure 4 Connection diagram for PQC 0602401-XX ............................................................. 26
Figure 5 Connection diagram for PQC 1204801-XX ............................................................. 27
Figure 6 Connection diagram for PQC 1204803-XX ............................................................. 28
Figure 7 Connection diagram for PQC 0614801-XX ............................................................. 29
Figure 8 Part of the connection diagram for 400/415 V networks with no neutral conductor 30
Figure 9 Part of the connection diagram for 690 V networks with a neutral conductor ........ 30
Figure 10 PQC Start screen (firmware version number may be different) ........................... 32
Figure 11 Menu structure 1 ................................................................................................... 36
Figure 12 Menu structure 2 ................................................................................................... 37
Figure 13 Menu structure 3 ................................................................................................... 37
Figure 14 Main menu 1/3 ..................................................................................................... 38
Figure 15 Main menu 2/3 ..................................................................................................... 38
Figure 16 Main menu 3/3 ..................................................................................................... 38
Figure 17 Changing the working language ........................................................................... 39
Figure 18 Identification: Stage + Connection ....................................................................... 40

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Figure 19 Identification: Connection .................................................................................... 40
Figure 20 Identification: Connection submenu .................................................................... 40
Figure 21 Identification: Stage ............................................................................................. 40
Figure 22 Identification: Stage submenu .............................................................................. 40
Figure 23 Identification: Manual .......................................................................................... 40
Figure 24 Identification: Manual submenu ........................................................................... 40
Figure 25 Connection identification started ......................................................................... 41
Figure 26 Capacitor stage identification started ................................................................... 41
Figure 27 Start-up completed ............................................................................................... 41
Figure 28 PQC overview L1 (1-phase) ................................................................................. 42
Figure 29 PQC overview L1 (3-phase) ................................................................................. 42
Figure 30 Capacitor stage statuses (1-phase, 6 stages) ......................................................... 42
Figure 31 Capacitor stage statuses (3-phase, 12 stages) ....................................................... 42
Figure 32 Control diagram .................................................................................................... 44
Figure 33 Control diagram with additional information ....................................................... 44
Figure 34 Zoomed in on control diagram ............................................................................. 44
Figure 35 Manual control ..................................................................................................... 45
Figure 36 Manual control enabled ........................................................................................ 45
Figure 37 Manual control: Switch out stages ....................................................................... 45
Figure 38 Manual control: Stages menu ............................................................................... 46
Figure 39 Example of a selected stage ................................................................................. 46
Figure 40 Message on failed attempt to switch in a stage .................................................... 47
Figure 41 Settings ................................................................................................................. 47
Figure 42 Control profiles .................................................................................................... 49
Figure 43 Control profile parameters ................................................................................... 49
Figure 44 Control response after setting target cos ϕ = 1, limitation = 0, parallel shift = 0 50
Figure 45 Control response after setting target cos ϕ = 0.92, limitation = 0, parallel shift = 0
50
Figure 46 Control response after setting target cos ϕ = 1, limitation = 0, parallel shift = +1.0
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Figure 47 Control response after setting target cos ϕ = 0.92 ind, limitation = OFF, parallel
shift = -1.0 51
Figure 48 Control response after setting target cos ϕ = 0.92 ind, limitation = +1.0 ............ 52
Figure 49 Control response after setting target cos ϕ = 0.92 ind, limitation = +1.0, parallel
shift = -1.0 52
Figure 50 Control response after setting target cos ϕ = 0.95 cap, limitation = -1.0, parallel
shift = 0 53
Figure 51 Phase L1 is the control phase ............................................................................... 53
Figure 52 General settings menu .......................................................................................... 54
Figure 53 Capacitor stages .................................................................................................... 55
Figure 54 Set limits 1/2 ......................................................................................................... 56
Figure 55 Set limits 2/2 ......................................................................................................... 56
Figure 56 Change set limit for switching cycle counter ....................................................... 56
Figure 57 Alarm management .............................................................................................. 57
Figure 58 Alarm management; here the Display alarm option ............................................. 57
Figure 59 Extensions menu .................................................................................................. 58
Figure 60 Modbus configuration .......................................................................................... 58
Figure 61 Factory default settings ........................................................................................ 59
Figure 62 Password prompt .................................................................................................. 60
Figure 63 Info / status 1/3 ..................................................................................................... 60
Figure 64 Info / status 2/3 ..................................................................................................... 60

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Figure 65 Info / status 3/3 ..................................................................................................... 60
Figure 66 PQC status overview ............................................................................................ 61
Figure 67 Total corrective power Q ...................................................................................... 61
Figure 68 Capacitor stages table ........................................................................................... 62
Figure 69 Diagram showing all stages at 100% ................................................................... 62
Figure 70 Diagram showing corrective power of all stages ................................................. 62
Figure 71 Switch cycle diagram ........................................................................................... 62
Figure 72 Current harmonics diagram, y-axis 100% ............................................................ 63
Figure 73 Current harmonics zoomed in, y-axis 25% .......................................................... 63
Figure 74 Voltage harmonics table ....................................................................................... 63
Figure 75 Manual frequency analysis ................................................................................... 64
Figure 76 About PQC ........................................................................................................... 65
Tables
Table 1 Connection types for current transformers in L1, L2 and L3 ................................... 33
Table 2 c/k settings at 400 V AC and 50 Hz ......................................................................... 34
Table 3 Key functions ........................................................................................................... 35
Table 4 Factory default settings ....................................................................................... 62
Table 5 Instrument versions ............................................................................................. 67
Formulas
Formula 1 Calculation of c/k ................................................................................................. 34

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1 Safety
1.1 OBJECTIVE
This operating manual has been prepared for persons who install, connect, commission and operate
the PQC Power Quality Controller.
1.2 SAFETY INSTRUCTIONS
No claims under guarantee shall be valid in the event of damages caused by failure
to observe the instructions in this operating manual. We shall not be held liable for
consequential damages!
Incorrect operation or failure to observe the safety instructions will invalidate all
claims under the guarantee, and no liability is accepted for any injuries to persons
or damages to assets arising therefrom or occasioned thereby!
DANGER!
The following instructions must be observed to prevent danger to life and limb or damage
to equipment and other assets:
• Installation and commissioning of the instrument in industrial plant must be
carried out in strict compliance with the standards IEC 61508 and DIN VDE
0801.
• Any other laws, standards, regulations and safety rules (IEC, EN, VDE, etc.)
relevant to this product and the protection of persons and assets must be
observed. In Germany, it is essential to comply with the Equipment Safety Act
(GSG) and the regulations of the German Social Accident Insurance Institutions.
In other countries, the equivalent local regulations must be followed.
• Installation, commissioning, modifications and retrofitting may only be carried out
by appropriately qualified personnel.
• In Germany, it is essential to comply with the regulations of the Social Accident
Insurance Institution covering electrical installations. In other countries, the
equivalent local regulations must be followed.
• The instrument contains live components at the AC supply voltage and must
therefore not be opened.
• If the instrument is visibly damaged, it must not be installed, connected or
commissioned.
• Only approved installation cables must be used.
• If the instrument does not work after commissioning, it must again be isolated
from the power supply.
• The instrument must only be employed on duties up to the specified maximum
power. Overloading the instrument can result in its destruction, create a fire
hazard or cause an electrical accident. The load ratings for the various
connections must not be exceeded.
• Do not expose the instrument to direct sunlight or high temperatures, as these
could damage it or shorten its service life.
• Do not install the instrument near to sources of heat such as radiators or other
devices that generate heat.

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• Do not expose the instrument to rain, water, dampness or high levels of humidity.
Avoid direct contact with water at all cost.
• Failure to observe the safety instructions can result in death, serious injury or
severe damage to equipment and other assets.
• In commercial premises, the local accident prevention regulations must be
complied with (e.g. in Germany, the regulations of the German Social Accident
Insurance Institutions for electrical installations and equipment).
• The safety of the system in which the PQC is incorporated is the responsibility of
the persons installing and operating the system.
• For safety reasons and to retain conformity with product approval requirements
(CE marking), the user is not permitted to convert or otherwise modify the
instrument.
• The instrument must always be handled with due care; if it is jolted, knocked or
dropped from even a low height, it will be damaged.
• This operating manual may be changed without notification. Please consult our
website www.schrack.com for the up-to-date version.
When work is carried out on the instrument terminals and connecting cables, there is a
risk of live components being touched inadvertently. The working voltage may present a
hazard to health or may even be life-threatening.
The risk to life and limb can be significantly reduced by observing the above safety
precautions.
• The user must ensure that all operators are familiarized with this operating manual and follow it at all
times.
• This operating manual must be read through carefully and completely before the instrument is installed,
connected, commissioned and operated. All actions taken must be in accordance with this operating
manual.
• The operating manual must be held for future reference.
• Wherever this symbol is shown, the documentation must be referred to.
1.3 INTENDED USE
The PQC Power Quality Controller is intended for the following applications within the scope of the
technical data (see Section 2, Technical data):
• Control of reactive power in stages. Output relays (switched outputs, stages) are provided for this purpose.
Capacitors can be connected to these via current-amplifying electromechanical devices (relays, contactors).
• Measurement of data relevant to network power quality, such as voltage, current and frequency, either in any
desired phase ‘L1’ or in all three phases L1, L2 and L3, depending on the instrument version (see Section 2,
Technical data); connection of an alarm contact rated within the allowable limits for the electrical parameters (see
Section 2, Technical data)
The PQC is intended for installation in stationary, weather-protected control cabinets and enclosures located
indoors. Exposure to dampness is not permitted. The instrument is installed vertically, usually on the outside of
the control cabinet or enclosure, so that the controls and display are accessible to the operator.
The USB port is a service interface provided solely for updating the PQC firmware. Users are not permitted to use
this USB port for any other purpose, and therefore must not connect any cable or device to it. When the PQC is in
operation, the USB port must not be touched. It is intended for connecting a battery-powered notebook.
1.4 IMPROPER USE
Any use of the instrument that deviates from its intended use is considered improper and therefore not
permitted. If the PQC is used in a way not specified in this operating manual, the protection supported
by the instrument may be adversely affected.

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1.5 REPAIR
Repairs may not be carried out by the customer or user. Should repair work be necessary, the customer
or user must contact Schrack Technik (contact addresses see: www.schrack.com):
1.6 SYMBOLS USED
Special instructions in this operating manual are marked by symbols.
The corresponding word that expresses the extent of the danger is also printed above the instructions.
In order to avoid accidents, death or injury and damage to assets, these instructions must be complied
with at all times.
Warning signs
DANGER!
Indicates an immediate danger that if not avoided can result in death or serious injury.
DANGER!
Indicates an immediate danger of electric shock that if not avoided can result in death or
serious injury.
Notes for the correct functioning of the instrument
CAUTION!
These instructions indicate dangers that could result in damage to equipment if the
instructions are not followed.
They can also cover aspects of environmental protection.
NOTE!
These instructions, when followed, serve to ensure the correct functioning and fault-free
operation of the instrument.

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2 Technical data
Power supply
• Supply voltage PQC version: PQC xxx240x-xx:
85–267 V AC (absolute limits), frequency 45–65 Hz or
100–377 V DC (absolute limits)
PQC version: PQC xxx480x-xx:
85–530 V AC (absolute limits), frequency 45–65 Hz or
100–750 V DC (absolute limits)
• Power draw maximum 5 VA
• Overcurrent protection External, maximum 2 A (slow-blow) specified
Inputs
• Voltage path measurement inputs PQC version: PQC xxxxxx1-xx: single phase
PQC version: PQC xxxxxx3-xx: 3-phase
3-phase 80 V AC – maximum 760 V AC (phase–phase,
absolute limits), this corresponds to 115–690 V AC networks,
electrically interconnected via high resistance, medium
voltage measurement via ../100 V transformer possible
Power failure detection after duration of a half-wave
• Current path measurement inputs PQC version: PQC xxxxxx1-xx: single phase
PQC version: PQC xxxxxx3-xx: 3-phase
x/5 A AC or x/1 A AC (transformer secondary current ≥ 15
mA), electrically isolated, power draw maximum 1 VA per
transformer connection, continuous overload rating up to 6 A
AC, transient overload maximum 10 A AC for 10 seconds
• Digital inputs and outputs PQC version: PQC xxxxxxx-x1:
Up to 5 × 5–24 V DC inputs, alternatively usable as up to
5 × 24 V DC, 100 mA outputs, electrically interconnected with
each other and the temperature input
• Temperature inputs PQC version: PQC xxxxxxx-x1:
1 × Pt100 or Pt1000 RTD, 4-wire or 2-wire configuration,
automatic detector type identification
2× NTC thermistor type TDK/Epcos-B57861S0502F040,
type No. 29-20094
Measurement range -50 – 200 °C
Electrically connected with the digital outputs
Outputs
• Output relays (control outputs,
capacitor stages)
Normally open with common pole P
PQC version: PQC 120xxxx-xx: 12 output relays and
PQC version: PQC 060xxxx-xx: 6 output relays,
AC-14 250 V AC, maximum 3 A or DC-13 30 V DC, maximum
3 A, mechanical service life 2 x 107 switching cycles,
electrical service life AC-14 at 3 A 1 x 105 switching cycles,
AC-14 at 0.5 A 2 x 106 switching cycles
PQC version: PQC 061xxxx-xx: 6 output relays
AC-14 440 V AC, maximum 3 A or DC-13 125 V DC,
maximum 3 A, mechanical service life 1 x 107 switching
cycles,
electrical service life AC-14 at 3 A 1 x 105 switching cycles,
AC-14 at 0.5 A 2 x 106 switching cycles

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Common supply conductor P to the output relays maximum 10
A
Note: utilization category AC-14 / DC-13 as per IEC 60947-5-1
For all PQC versions in areas where UL / CSA standards
apply:
3 A 250 V AC cos ϕ = 1 at 85 °C
3 A 30 V DC L/R = 0 ms at 85 °C
• Alarm contact
Volt-free, normally open,
AC-14 250 V AC, maximum 3 A or DC-13 30 V DC, maximum
3 A, mechanical service life 2 x 107 switching cycles,
electrical service life AC-14 at 3 A 1.5 x 105 switching cycles,
AC-14 at 0.5A 2 x 106 switching cycles
Note: utilization category AC-14 / DC-13 as per IEC 60947-5-1
In areas where UL / CSA standards apply:
3 A 250 V AC cos ϕ = 1 at 85 °C
3 A 30 V DC L/R = 0 ms at 85 °C
• Digital outputs
PQC version: PQC xxxxxxx-x1:
Up to 5 × 24 V DC, 100 mA outputs, electrically interconnected
with each other and the temperature input, alternatively usable
as up to 5 × 5–24 V DC inputs.
Interfaces
• Modbus RTU connection
PQC version: PQC xxxxxxx-2x:
120 Ω terminating resistor required at the end of the bus system
Connections Via pluggable screw terminals
• Instrument power AUX
Conductor cross section max. 2.5 mm², min. 0.2 mm2,
PQC version: PQC xxx240x-xx:
Insulation rating: min. 250 V AC, 80 °C
PQC version: PQC xxx480x-xx:
Insulation rating: min. 500 V AC, 80 °C
• Protective earth PE
Via 6.3 mm female slide connector
Conductor cross section at least equal to the largest conducto
r
cross section of the AUX phases, the voltage measurement
connections, the output relays and the alarm connections;
insulation colour yellow/green
• Voltage measurement inputs
L1, L2, L3, N
Conductor cross section max. 2.5 mm², min. 0.2 mm2
Insulation rating:
Example 1: 230 V AC, select at least 250 V AC, 80 °C
Example 2: 690 V AC, select at least 800 V AC, 80 °C
• Current measurement inputs
L1, L2, L3, terminals S1 and S2 in
each case
Conductor cross section max. 2.5 mm², min. 0.2 mm2
Insulation rating: min. 250 V AC, 80 °C
• Output relays (control outputs,
capacitor stages)
Conductor cross section max. 2.5 mm², min. 0.2 mm2
PQC version: PQC xx0xxxx-xx: 250 V relays
Insulation rating: min. 250 V AC, 80 °C
PQC version: PQC xx1xxxx-xx: 440 V relays:
Insulation rating: min. 500 V AC, 80 °C

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• Alarm contact Conductor cross section max. 2.5 mm², min. 0.2 mm2
Insulation rating: min. 250 V AC, 80 °C
• USB for updates (service interface) USB Micro-A and Micro-B ports
• Digital inputs and outputs PQC version: PQC xxxxxxx-1x:
Conductor cross section max. 1.5 mm², min. 0.14 mm2
Insulation rating: 50 V DC, 80 °C
• Temperature inputs PQC version: PQC xxxxxxx-1x:
Conductor cross section max. 1.5 mm², min. 0.14 mm2
Insulation rating: min. 50 V DC, 80 °C
• Modbus RTU connection PQC version: PQC xxxxxxx-2x:
Conductor cross section max. 1.5 mm², min. 0.14 mm2
Insulation rating: min. 50 V DC, 80 °C
Note: 0.14 mm2 = AWG 26; 0.2 mm2 ≈ AWG 25;
1.4 mm² ≈ AWG 16; 2.5 mm² = AWG 14
Design data
• Dimensions W x H x D: 144 mm × 144 mm × 70 mm casing
W x H x D: 144 mm × 165 mm × 70 mm including connectors
• Mounting Front of panel in 138 mm x 138 mm cutout to IEC 61554, held
by four retaining lugs at the corners of the casing
Maximum screw tightening torque 0.4 Nm
• Weight approx. 770 g without packaging
• Ingress protection Front of instrument when mounted in cabinet IP40, when
mounted in cabinet with upgrade kit (Item No. 20-50015) IP54;
rear of instrument and terminals IP20; all as per EN 60529
Pollution degree 2 as per EN 61010-1:2011-07
• Electrical design Casing protection class I as per EN 61140
Working voltage up to max. 760 V AC absolute value at voltage
measurement inputs.
TNV1 circuits, some of which interconnected:
digital inputs and outputs, optional temperature inputs, optional
Modbus connection.
• Casing design Flammability rating UL 94 V-0 according to casing
manufacturer
Impact resistance IK06 as per EN 61010-1:2011-07, 8.2.2
• Service life At +25 °C ambient temperature 15 years
• EMC EMC as per EN 61326-1
EN 61000-4-2, electrostatic discharge: air 8 kV and contact 6
kV with horizontal and vertical coupling plane
EN 61000-4-3, radiated immunity (EMS) 80 MHz – 1 GHz,
horizontal and vertical, level 10 V/m = industrial environment
radiation, Class A
Hardware version V1.0: EN 55022A EMI 30 MHz – 1 GHz =
industrial environment, Class A
From hardware version V1.1: EN 55022A EMI 30 MHz – 1 GHz
= office and residential area, Class B
EN 61000-4-6, immunity to conducted disturbances, level 10
V RMS, 150 kHz – 80 MHz 1
1 The standard radio-frequency field test as per EN 61000-4-6 (EMC immunity) calls for amplitude modulation at a modulation frequency of 1 kHz. However, this frequency
lies within the measurement range of the instrument in its intended use (20th harmonic of 50 Hz = 1 kHz). It is therefore to be expected that the measuring circuit clearly
responds to this. For this reason, the radio-frequency field test can only be carried out without amplitude modulation.

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EN 61000-4-4, burst immunity, 1 kV capacitive coupling, 2 kV
injection into power supply cable and voltage measurement
inputs
EN 61000-4-5 surge immunity, 2 kV injection into power supply
cable and voltage measurement inputs
Ambient conditions
• Temperature range
-20 °C to +60 °C, noncondensing
• Installation altitude
Maximum height above sea level 2000 m
Measuring system
• Accuracy
Voltage and current measurement ±1% of full scale reading at
50/60 Hz and 25 °C ambient temperature
• Averaging function
Over 1 second, updated every 100 ms
• Harmonics
Measured via Lx–N
All even and uneven harmonics up to the 19th

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3 Instrument description
3.1 FUNCTION
The PQC Power Quality Controller is a reactive power control relay. It continuously calculates the reactive and
active power components of the supply network using the measurement data from the current path (current
transformer) and the voltage path (voltage measurement connection). If the reactive power component exceeds
certain thresholds, which the PQC has determined during the calibration procedure or which have been set as
described, switching commands are given via the instrument outputs. If the inductive reactive power is greater
than the value preset during instrument configuration (target cos phi), after an adjustable time delay one or more
of the PQC control contacts are closed. The PQC thus switches capacitor stages in as required in order to restore
the target power factor. If the inductive reactive power component of the loads reduces again, this causes
capacitor stages to be switched out. The PQC makes a variety of options possible for customizing the control
settings to suit the individual application. The clear overview in the display provides effective monitoring of power
factor correction. So-called ‘cyclic switching’ is a useful feature for prolonging the service life of the installation,
since it ensures that all capacitor stages of the same power rating are on average switched in equally frequently.
3.2 REGENERATION
The PQC has a four-quadrant control function. If active power is fed back into the supply network, for example by
combined heat and power systems, the PQC continues to correct for the reactive power drawn from the supply
network. When this regeneration occurs, the active power P is displayed with a minus sign before it. Regeneration
mode is also indicated by a symbol appearing on the display screen.

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4 Mounting the instrument
4.1 SUITABLE LOCATION
See Section 1.3, Intended use.
Hardware version V1.0: This is a Class A device. In office and residential areas, it can cause interference to radio
reception. In this case, it may be necessary to take appropriate precautions with the installation.
4.2 INSTALLING THE INSTRUMENT
Figure 1 PQC dimensions in mm
Upgrade kit for IP54:
In the optional upgrade kit (type No. 20-50015) a gasket is available that must be used when mounting the PQC
in control cabinets with IP54 ingress protection. It is fitted in the groove at the rear of the instrument’s front panel
(moulded polymer) before the PQC is mounted in the cutout. The gasket seals the gap between the PQC front
panel and the wall of the control cabinet.
DANGER!
The rear of the panel-mounting PQC inside the control cabinet or enclosure only has IP20
ingress protection. Adequate protection against inadvertently touching live components
must be provided, and the ingress of dust and water must be prevented by ensuring that
the instrument is installed in a suitable enclosure (e.g. control cabinet or distribution
panel).
DANGER!
The PQC must not be installed in a hazardous zone, as its switching operations generate
sparks that could ignite flammable gases.
Only install the instrument in areas where there is no danger of a gas or dust explosion.
The PQC is designed for mounting in a 138 mm x 138 mm cutout to IEC 61554 in the front of a control cabinet.
It is held in place by four retaining lugs in the corners of the instrument.
7
70
63
37
12
12
168 144
135,5
Schutzleiter - Zunge
6,3 mm × 0,8 mm
Earthing tab
6.3 mm ×0.8 mm

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Fitting:
• Preparation: the four retaining lugs at the corners of the instrument are swivelled to lie flat behind its front
panel by turning the retaining screws (accessible from the front) anticlockwise.
• Insert the sheet-metal rear of the PQC through the cutout provided in the control cabinet until fully home
(having first fitted the IP54 gasket in the groove behind the PQC front panel when appropriate).
• Press the PQC front panel gently against the control cabinet exterior and tighten the four retaining
screws at the corners by turning them clockwise, applying a torque of no more than 0.4 Nm. This causes
the retaining lugs to swivel outwards and be drawn toward the inner side of the cabinet wall until they are
held tightly up against it.
DANGER!
To avoid accidents, the following must be observed:
- The PQC must be installed in accordance with its intended use before power is switched on.
- All the connectors supplied with the instrument must be plugged in.
If the above precautions are taken, the danger to life and limb can be significantly reduced.
DANGER!
To prevent the PQC overheating, the following must be observed:
- The PQC must be installed in an adequately ventilated space, and its rear and sidewalls must not be
covered.
- No sources of heat must be located in the vicinity.
- The PQC must not be exposed to direct sunlight.
If the above safety precautions are taken, the risk of damaging equipment and assets or
endangering life and limb can be significantly reduced.
IMPORTANT SAFETY NOTICE!
To avoid accidents, the following must be observed:
When the panel-mounting instrument is fitted in the front of a control cabinet for its
intended use, there is a danger that its four retaining screws could become live and
therefore a safety hazard if there is a fault in the wiring adjacent to the instrument. If a wire
at a dangerous voltage works loose, it could make electrical contact with one of the four
retaining screws. This means that it cannot be excluded that the head of the screw, which
can be touched from outside the cabinet, could become live. In rare cases this could
constitute a danger to life and limb.
At the location where the panel-mounting instrument is installed (e.g. control cabinet,
enclosure), all wires and cables must be securely fastened or grouped in harnesses to
ensure that any stray wire or strand cannot contact one or more of the instrument's
retaining screws, thus making it or them live and therefore dangerous.
If the above safety precautions are taken, the risk of damaging equipment and assets or
endangering life and limb can be significantly reduced.

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5 Installation
5.1 ELECTRICAL CONNECTIONS
The instrument is connected as shown in the diagrams in Section 5.7.
DANGER!
The following instructions must be observed to avoid danger to life and limb:
• When the instrument is being installed or serviced, the instrument and the
electrical system must be isolated from the power supply.
• The isolated electrical system must be locked out to prevent its being
inadvertently switched on again.
• It must be verified that none of the terminals are live!
• The earthing tab must always be the first connection that is made (see Section
5.2, Earth connection).
• The power supply and voltage measurement terminals are live and must not be
touched (risk of electric shock)!
• The measurement terminals L1, L2, L3 and N, the AUX power supply terminals
and both alarm contacts must be short-circuited during any work carried out on
the instrument.
• All live components in the vicinity must be covered to prevent inadvertent
contact.
• If the power supply voltage and the voltage measured exceed the values
specified in this operating manual and stated on the instrument, this may cause
damage to the PQC. Consequential damage to other parts of the installation is
also possible.
• The instrument power supply circuit AUX must be protected externally by a 2 A
slow-blow 250 V AC fuse. One such fuse is required when the power is from an
L–N connection, but two fuses must be installed if an L–L connection is used.
• A disconnecting device must be installed so that the connections of the PQC
can be isolated from the electrical system and building electrical installations.
• Only the specified and appropriate voltages and signals may be connected to
the respective terminals and ports provided for them.
• The cross-sectional areas of all cables used must be adequate for the purpose.
• Suitable measures must be taken to prevent cables operating at the power
supply voltage being inadvertently pulled out and twisted.
• A disconnecting device, such as an isolator or circuit breaker, must be fitted in
the building electrical installation in a suitable location, accessible by the user
and appropriately labelled as a disconnecting device for the PQC. It must be
able to isolate all cables operating at the power supply voltage from the
instrument.
• If flexible stranded cables with their total cross-sectional area assembled from
several fine filaments are used for the connections, ferrules must be crimped
onto their ends. It must be ensured that no individual filament has been left out
of the ferrule.
When work is carried out on the connecting cables and the instrument terminals, it is
possible that live components may be touched inadvertently. If this occurs, the voltage
present may be injurious to health or may even have fatal consequences.
The risk to life and limb can be significantly reduced by observing the above safety
precautions.

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NOTE!
The instrument can be damaged by incorrect operation.
• Only the specified and appropriate voltages and signals may be
connected to the respective terminals and ports provided for them.
• The cross-sectional areas of all cables used must be adequate for the
purpose.
• The required cable types are specified in Section 2, Technical data.
If any incorrect cables, voltages or signals are applied to the terminals, this can result in
damage to the PQC and the electrical installation.
DANGER!
To avoid accidents, the following must be observed:
A
t the PQC installation site (e.g. control cabinet, enclosure), all wires and stranded cables
must be adequately secured or grouped in harnesses to ensure that no conductor can
work free and touch one or more of the instrument retaining screws so as to make them
live and a source of danger.
If the above safety precautions are taken, the risk of damaging equipment and assets or
endangering life and limb can be significantly reduced.
NOTE!
If flexible stranded cables used for the connections, insulated ‘short’ ferrules 6 mm in
length must be crimped onto their ends.
5.2 EARTH CONNECTION
DANGER!
To avoid accidents, the following must be observed:
• The earthing conductor PE must always be connected to the PQC instrument
casing before any other connections are made.
• The PE conductor cross section must be at least equal to that of the largest
conductor of the AUX phases, the voltage measurement connections, the output
relays or the alarm connections. Its insulation colour is yellow/green. Earthing
connections for network power circuits must have at least the same current-
carrying capacity rating as the circuits themselves.
• If the earthing tab has broken off, the PQC must not be started up. The
instrument must either be repaired or replaced.
• The PQC may only be put into service when the earthing conductor is
connected to it.
If the above safety precautions are taken, the risk of damaging equipment and assets or
endangering life and limb can be significantly reduced.
The earthing conductor PE must always be connected to the PQC instrument casing.
An earthing tab is provided for this in the rear wall of the casing. It is marked with the earthing
symbol as per EN 60617-2 shown at left.

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5.3 SUPPLY VOLTAGE
The instrument power supply circuit AUX must be protected externally by a fuse, either
• 2 A slow-blow, 250 V AC (PQC version: PQC xxx240x-xx), or
• 2 A 500 V AC time delay (PQC version: PQC xxx480x-xx).
One such fuse is required when the power is from an L–N connection, but two fuses must be installed if an L–L
connection is used.
A disconnecting device must be installed so that the connections of the PQC can be isolated from the electrical
system and building electrical installations.
The connection diagrams (see Section 5.7) show instruments with 6 or 12 output relays.
DANGER!
To avoid accidents, the following must be observed:
• The safety instructions in Section 5.1, Electrical connections
• Connection of the instrument power supply as specified in this manual
• Not exceeding the specified maximum operating voltage at the AUX power
supply terminals (see Section 2, Technical data)
When work is carried out on the instrument terminals and connecting cables, there is a
risk of live components being touched inadvertently. The working voltage may present a
hazard to health or may even be life-threatening.
If the above instructions are followed, and the precautions specified in Section1.2, Safety
instructions, are taken, the risk of damaging equipment and assets or endangering life
and limb can be significantly reduced.
With these instrument types (see Section 9, Instrument versions), provided that the specified voltage
limits are not exceeded, it is possible to use phase–phase or phase–neutral connections. For typical
examples, see Figures 8 and 9.
CAUTION!
- The cables and the earthing conductor leading to the instrument must be permanently
connected. It is not permitted for these to have plug-in connections, except for those
connectors supplied with the instrument.
- An external disconnecting device, such as an isolator or circuit breaker, must be fitted in
the power supply line to the instrument. This must be located in the vicinity of the PQC
and must be able to isolate all cables connected to the AUX terminals. It must be suitable
for this application, comply with the requirements of IEC 60947-1 and IEC 60947-3, and
be appropriately labelled as a disconnecting device for the PQC. This device must not
disconnect the earthing conductor.

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5.4 VOLTAGE MEASUREMENT
Depending on the instrument type (see Section 9, Instrument versions), the PQC can measure one, two
or three AC voltages. The voltage measurement inputs are electrically interconnected via high
resistances. See Section 2, Technical data, for the measurement ranges. DC voltages cannot be
measured.
The PQC voltage measurement inputs are designed for 100–690 V AC networks.
It is possible to measure medium voltages using an x/100 V transformer.
It is not necessary to provide external overcurrent protection in the voltage measurement circuits since
these are safety impedance-protected. In this case, a short-circuit-proof cable (double insulated
stranded wire) must be used to connect the voltage measurement inputs.
DANGER!
To avoid accidents, the following must be observed:
• The safety instructions in Section 5.1, Electrical connections.
When work is carried out on the instrument terminals and connecting cables, there is a
risk of live components being touched inadvertently. The working voltage may present a
hazard to health or may even be life-threatening.
If the above instructions are followed, and the precautions specified in Section 1.2, Safety
instructions, are taken, the risk of damaging equipment and assets or endangering life
and limb can be significantly reduced.
Instrument types with single-phase measurement (see Section 9, Instrument versions):
For single-phase measurement, the terminals L1 and N are connected as shown in the connection diagrams in
Section 5.7. The voltage can be measured between any two phases or between any phase and neutral.
Instrument types with 3-phase measurement (see Section 9, Instrument versions):
For 3-phase measurement, the terminals L1, L2, L3 and N are connected as shown in the connection
diagrams in Section 5.7. Phases L1, L2 and L3 must be connected in correct phase sequence.
If an instrument of the 3-phase type is used for single-phase measurement, only the terminals L1 and
N are to be used. In this case, it is necessary to connect the terminals L2 and L3 to terminal N in order
to avoid false readings being obtained.
For 3-phase measurement, it is advisable to connect the N terminal as well. This enables the high
measurement accuracy of the PQC to be achieved when measuring phase–neutral voltages and the
parameters derived from these. If no neutral conductor is present, the N terminal can be left
unconnected. However, this is only advisable when the phases are symmetrically loaded.
NOTE!
With instrument types designed for three-phase measuring, the voltage measurement
inputs not in use must be commoned with the terminal N. This is necessary, for example,
with single-or two-phase connections.
If this is not done, phantom measurement readings may be displayed for the inputs that
are not in use.
With three-phase measurement, automatic connection identification is not possible.